Generally, in the field of semiconductor technologies, many kinds of transistors having different characteristics such as threshold voltage (Vth), speed and power consumption are known. Depending on the field of application, a transistor type having a high or a low threshold voltage is desired. Moreover, there are several concepts for increasing the channel length of a transistor. In a similar manner, an appropriate transistor type can be selected depending on the desired application.
In addition, it is often desired to combine two transistors having different characteristics on one single chip. In this case, a method might be useful by which transistors having different characteristics can be manufactured in the same semiconductor substrate.